3種藥劑對象耳豆根結線蟲卵及2齡幼蟲的影響

楊雪婷 楊紫薇 丁曉帆

摘要 為了篩選對象耳豆根結線蟲Meloidogyne enterolobii防治效果好的藥劑，本文采用浸蟲法分別測試了3%阿維菌素微乳劑、41.70%氟吡菌酰胺懸浮劑及20%噻唑膦水乳劑不同濃度、不同處理時間對象耳豆根結線蟲2齡幼蟲的致死作用，以及對卵孵化和卵胚胎發育的影響。結果表明，3%阿維菌素微乳劑對2齡幼蟲致死作用最強，LC50僅為0.017 mg/L，對卵孵化抑制作用最好，0.16 mg/L處理24 h抑制率達到100%;41.70%氟吡菌酰胺懸浮劑次之，對2齡幼蟲LC50為0.310 mg/L，2.5 mg/L處理24 h卵孵化抑制率為92.47%;20%噻唑膦水乳劑最差，對2齡幼蟲LC50為4.209 mg/L，3.125 mg/L處理24 h卵孵化抑制率僅為65.54%;3種藥劑均能影響象耳豆根結線蟲卵胚胎發育，隨著藥劑濃度、處理時間的增加，死亡卵比例逐漸增高，且藥劑處理使多數卵胚胎停止在單細胞和1齡幼蟲階段。綜上，3種供試藥劑對象耳豆根結線蟲均有較好的抑殺作用，抑殺效果依次為3%阿維菌素微乳劑>41.70%氟吡菌酰胺懸浮劑>20%噻唑膦水乳劑。研究結果將為更好地防治象耳豆根結線蟲提供理論依據。

關鍵詞 象耳豆根結線蟲; 生物測定; 殺線蟲劑

中圖分類號： S482.51

文獻標識碼： A

DOI： 10.16688/j.zwbh.2021064

Abstract In order to screen effective nematicides， the effects of abamectin 3% ME， fluopyram 41.70% SC and fosthiazate 20% EW on the embryonic development， egg hatching and juvenile mortality of Meloidogyne enterolobii were determined by dipping method with different concentrations of these nematicides. The results showed that abamectin 3% ME showed the best toxicity to the second stage juveniles （J2） with the lowest LC50 value of 0.017 mg/L， and eggs hatching inhibition rate reached 100% treated by 0.16 mg/L of abamectin 3% ME within 24 hours. Fluopyram 41.70% SC was the next， with LC50 value of 0.310 mg/L， and inhibition rate reached 92.47% treated by 2.5 mg/L. While the toxicity of fosthiazate was the lowest， with LC50 value of 4.209 mg/L and 65.54% inhibition rate treated by 3.125 mg/L. All three nematicides could affect the embryonic development. The proportion of dead eggs was positively correlated with nematicides concentration and treated time. The nematicides made most embryos suspend at the stage of single cell and first stage juveniles. These results demonstrated that three tested nematicides have certain inhibitory effects on eggs and J2 of M.enterolobii， and the inhibitory effect was abamectin 3% ME>fluopyram 41.70% SC>fosthiazate 20% EW in order. The above results will provide a theoretical basis for better control of M.enterolobii.

Key words Meloidogyne enterolobii; bioassay; chemical nematicide

海南省是中國重要的熱帶作物和反季節瓜果蔬菜生產基地[1]，作物種類繁多，連作栽培普遍，使土傳病害逐年加重，其中根結線蟲Meloidogyne spp.病害尤為嚴重。根結線蟲危害蔬菜根部，在幼根、須根上形成根結，重病植株矮小，葉片發黃，呈點片缺肥狀，不結實或結實不良[24]。近些年來，象耳豆根結線蟲M.enterolobii已成為危害海南當地瓜果蔬菜的優勢種群，單一檢出率達到62.37%，與南方根結線蟲復合侵染檢出率為8.47%[56]，與其他主要根結線蟲不同的是，象耳豆根結線蟲能克服Mi、N和Rk等抗線蟲基因介導的抗性反應，能在抗性番茄、辣椒等茄果蔬菜上寄生繁殖，造成產量損失[79]。……